[GRASS-user] help with r.hants

[Veronica Andreo]

Hola Leo!

> Hello community!
>
> I would like to ask a little help for a brand new 7 GRASS module: r.hants.
> In this module there are some option that can be chosen. One of them is:
>
> fet=float - Fit error tolerance
>
> Anyway in the manual there is no explanation about how to use this option,
> that actually seems to be quite useful.
> I would like to know how to use it. Should this error tolerance be
> indicated as a percentage?

There's no specific explanation for that parameter, you are right... But
there's the reference paper at the bottom of the manual page where you can
find some more help

Roerink, G. J., Menenti, M. and Verhoef, W., 2000. Reconstructing cloudfree
NDVI composites using Fourier analysis of time series. International
Journal of Remote Sensing, 21 (9), 1911-1917. DOI:10.1080/014311600209814
<http://dx.doi.org/10.1080/014311600209814>

Anyway, as far as I understand this "fet" parameter is relative to the
variable you are working with, in terms of the values of the variable how
much error would you admit in the reconstruction. For example, in ndvi, I
guess it should be in the order of 0.1.

In my case, to set values of different parameters (as there's no a fixed
rule and is more a kind of try and error thing), I changed one parameter at
a time, letting the rest with a fixed value... So, I could see the effect
of changing each parameter.

Hope this helps a bit!

Cheers,
Vero
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